Connecting rod structure



L. 4. MGK'ONE April 9], 1929.- CONNECTING ROD STRUCTURE: Re. 17,265

Original File? Feb 1927 20 7 7 M794 /9 Me Q #2 17222672507 0 JMchozvg Reiscued Apr. 9, 1929.

UNITED. STATES, PATENT OFFlCE;

LEO J. mcxonn, or nn'rnorr, iv ncnrean- CQNNECTING-ROD STRUCTURE.

OriginaLN'o. 1,648,720, dated September2'i3 1827, s erial No. 166,955, filed February 9, 1927.

for reissue filed April 19, 1928. Serial No. 271,374.

This invention relates toan internal combust1on-eng1ne especially to suchlan engine of thehigh speed type such as used in automobiles and aeroplanes, and the invention is par ticularly directed to the wrist pin and connecting rod structure of such an engine. It,

is well known to those skilled in the art, that theoretically the axes of wrist pin and crank shaft bearings should be exactly perpendicular to the axis of said cylinder bore. In spite of past efforts of engine builders, however, the axis of the wrist pin is not always exactly perpendicular to the axis of the piston or cylinder bore This condition causes the connecting rod axis to be thrown out of the plane passing through the axesof the piston and cylinder and whichis perpendicular to the axis of the crank shaft. The connecting rod thus tends to cant the piston and the piston bears more strongly against the wall of the cylinder on" one side than on the other, thus resulting in an unequal wear on the piston and in scoring and scratching of the cylinder and piston. The vpistons are often slightly canted so as to bearunevenly on the cylinder Application vide apiston having a wrist pin with asemispherical bearing and a connecting rod hav mg a semi-spherical bearing engaging the no bearing on said wrist pin, a portion of the connecting rod bearing being yieldable.

It 1s more specifically an object of this invention to provide a passage having a wrist pin with a semi spherical bearing thereon and a connecting rod having a bearing provided walls throughthe uneven expansion thereof,

and there is often enough movement between the walls of the piston and cylinder for the connecting, rod to rock the piston slightly when it reverses its stroke. This results in what is generally known as piston slap and this is the result of mal-aline1nent of the cylinder, piston and connecting rod. Such piston and cylinder troubles are now very common in automobiles and so affect the cylinders and pistons that refitting of the pistons and reboring of the cylinders is frequcntly necessary. This invention 1s an improve l'nent upon that disclosed andclaiined in a prior Patent 1,491,155, granted to applicant April 22, 1-924. With the structure disclosed in said patent,the piston slap is eliminated. It is desirable, however, that a close fit be maintained between the connecting rod and the wrist pin. 'If the bearing on the connect-- ing rod which engages the wrist pin becomes worn so as to cause a little play, an 010 whenable knock or slap will loccurif the piston moves slightly laterally.

It is an object of this invention, therefore, to provide a'piston, connecting rod and wrist pin structure which will permit of lateral movement of the connecting rod without moving the piston and will at all times maintain the portions shown in vertical section;

holding means.

with a cap, a member in the cap forming part of the bearing on thewrist pin which is actedupon by resilient means in the cap for holding said memberin firm engagement with the wrist pin.

It is also an object of the invention to provide a piston, connecting rod and wrist pin structure in which the connecting rod has a yielding bearing on the wrist pin.

'1hese and other objects and advantages of the invention will befully set forth in the following description made in connection with the accompanying drawings, in. which like reference characters refer to similar parts throughout the several views and in which Fig.1 is a central section through the assembled piston and connecting rod;

Fig. 2 is a view in side elevation of the upper end of the connecting rod and wristv pin, a portion being broken away and other portions being shown in vertica section;

Fig. 3 is a perspective view partly in section of a portion of the connecting rod and wrist pin bearing; n

Fig. i is a view in side elevation of the wrist pin showing the bearing holding means thereon partly in section;

Fig. 5 is ancnd view of the wrist pin with Fig. 6 is a view in side elevation of one form of holding means for the'wrist pin bearing; and i Fig. 7 is a view of a modified form of such Referring to the drawings, a piston such as used in an automobile engine is illustrated as 10 having therein piston ring grooves 10.

The piston has bosses 10 adjacent its central portion one of which is bored to receive the sleeve or bushing 11. One of the bosses 10 is bored to receive the'wrist pin 12 and the other boss is bored to a larger diameter to g receive a sleeve or bushing 11, which sleeve 11 is bored to receive the other endof the wrist pin 12. The wristpin 12 has a groove- 12 formed therein cross section, which extends around said wrist pin, and a ring 14: such as shown in Fig. 6 is disposed in the groove 12. A se1ni spl1eri cal bearing member 15 constructed in two halves is placed on the wrist pin 12 and has a circumferential groove at its central portion of semi-circular shape in cross section, which groove embraces the ring 14. The member 15 is made in two pieces and as-shown in Figs. 1 and 3, has its outer surface of semispherical shape. The member 15 is embraced 'by the upper end of the connecting rod 16,

said connecting. rod'h 'ving a hub 16 at its lower end, bored to receive the bushing 16 in which the crank shaft is journaled. The connecting rod 16 has a lower'bearingpon tion 16 which is formed on its inner surface to fit the member 15 and said bearing portion has oppositely projecting flanges 16 A cap member 16 is provided for the connecting rod, having oppositely extending flanges 16 alining with and engaging the flanges 16, said flanges being secured together by the studs 17 threaded into the flange 16 and being equipped with the nuts '18. The cap member 16 has a central up-' standing boss bored to form the recess 16 and having a small hole extending through the top thereof. A member ,19'lS disposed forined' on its inner sur face to fit the top of the member 15 and having a cylindrical portion 19 fitting loosely in the recess 16 at-the lower end thereof and having further a stem .19 extending centrally through the recess and througli the opening in the top of the boss on cap 16.-

' p A coiled compressionspring 2O surrounds the then compressed in the groove 12.-

stem 19", bearing at one end against-the top of the recess 16*- and-at its lower end against the shouldered top of the portion 19.

' In assembling the device, the wrist pin 12 will have the ring 14 placed thereon, which ring, if desired, can be slightly expanded and moved over the end of the wrist pin and The bear ing 15is then placed on'the wrist pin and the wrist pin can be inserted through the openingin boss loiwhich receives sleeve 11, the sleeve either being placed in said boss in thewrist pin orbeing subsequently placed in position. The members 19 and 20 are then placed in the cap 16 and the cap placed over the member 15 and engaged with the lower portion of the connecting rod. The nuts 18 are thenplaced the same tightened. The pistonand connecting rod are then assembled. p v r In operation the piston 10 will be reciprocated by the explosion in the engine cylinder and the connecting rod willrevolve at its lower end with the crank shaft. Should of semi-circular shape in I on the studs, 17 andv any lateralmovements occur in the piston, they can be accommodated by the member 15 rocking inside otthe semi-spherical bearings in the upper end of the connecting rod. The membe1i19 forms the upper bearing for the wrist pin or the member 15 and this member will always be held in firm engagement with the memberl5 by the spring 20. There is no chance, therefore, for wear to occur around the member 15 or in the connecting rod bearing which might cause a knock or slap in lateral movements of the piston. The member 19 is held in proper position by the members'li)" and 19 Theconnecting rod, wrist pin an,d"pis'ton thus function perfect ly and silently. The structure is especially designed for very high speed .engines such as now used on aeroplanes and high speed automobiles.

If desired, two rings such as shown as 2]. in Fig. 7 can be placed in the groove 12 of the wrist pin and the member 15 placed over these rings. 7

From the above description it is seen that applicanthas provided a very simple and of ficient structure of piston, wrist pin and con opening in the side so that the piston has very little, if any, bearing on the cylinder below the ring grooves or inthe skirt portion thereof. With such pistons ifthe cylinder is out-of-rou'nd or the piston and cylinder are, I

not p erfectly alined, a rocking movement of the piston is caused which is liable to cause i 4 a piston slap. The firm bearing on the wrist pin caused by the spring 20 in applicants de vice pressing on the member 19 retards thisrocking movement-ofthe piston so that the same is not quickly made and the slap-is substantially eliminated.

Furthermore, with v the-yieldingly mounted portion 19 it-is not necessary to machine the bearing in the connecting rod which bears on the wrist pin with minute accuracy. The

semispherical bearingin-the connecting rod on: the lower portion oifiaewrist pin can be colned. The bearing "surface of-the member 19 also need not. be machined withgreat accuracy. The same will wear and take the sha e of the wrist-pin hearing as will also the ow'er portion of the connecting rod. At

the-same time, .a firm and will bemaintained. o

It will, of'pourse, be understood that various changes may be made in the form, de-

parts, without departing from the scope of a-pplicants invention, which} generally stated, consists in a device capable of carry.- ing out the objects above set forth, in the perfect-bearing tails, arrangement and proportions of the V ing a yieldingly mounted portion.

novel parts and combinations of parts disclosed and claimed in the appended claims.

What is claimed is 1. In combination with an engine cylinder, a piston adapted to move therein, awrist pin journaled therein, a semi sphericalbearing-intermediate the ends of said wrist pin,

' and a connecting rod having a semi-spherical bearing fitting. over said bearing, said semis spherical bearing on the connecting rod hav- 2. In combination with an engine cylinder, a piston adapted to move thergnn; a wrlst pin ournaled therein, a semi-spherical bearing intermediate the ends of said wrist pin,

and a connecting rod havinga rigidlower' portion with a semi-spherical bearing fittingover said semi-spherical bearing on the wrist pin and having a resilientlymounted upper portion connected thereto fitting over the 1 top of the semi-spherical bearing on the wrist 1n; A g

3. In combination with an engine cyllnder, a piston adapted to move therein, awrist'pin 1ournaled therein, a seml-spher cal bearing intermediate the ends'of said wrist pin, a

connecting rod having a semi-spherical hearing fitting over said bearing on the wrlstipin 1 and a member resiliently mounted in said a part of thesemi- 7 connecting rod forming spherical bearing thereof. v I

4. In combination with an engine cylinder, a piston adapted to move therein, a wrist pin journaled therein, asemi-spherical bearing intermediate the ends of said wrist pin, a

, connecting rod, a capon said rod, a member carried in said cap bearing against said semispherical bearing on said wrist pin, and re-. silient means in said cap constantly urging said member against said wrist pin bearing;v

5. A connecting rodv having a lower semispherical bearing fittingover a- .portio'n of the semi-spherical bearing on said'wristpin, a-

cap for said connecting rod having arecess formed therein, a member carried in said cap having a semi-spherical bearing fitting over the other part of said semi-spherical bearing on the wrist pin, said member having a portion extending through said recess and a spring in said recess bearing upon said memher to hold the same in engagement with said semi-spherical bearing on the Wrist pin.

' "6L In combination with a piston for an in ternal combustion engine of. an automobile, a WIISbPlIl ournaled there n having a bore of uniform diameter, a connectingrod comprising a portion embracing and engaging said wrist pin, said portion having a circumferential groove therein about said 'wrist pin, said wrist pin also having a circumferential groove therein substantially alined with said groove in said portion, and means embracing said wrist pin and seated in and fitting the V groove therein and extending into the groove insaid connecting rod portion, whereby said connecting rod is held from on said wrist pin.

tomobile engine. and a wrist pin journaled therein, saldwrist' pin having-a shallow c1rlatei'al movement- 7; In combination with a piston of an -aucumferential groove therein adjacent its central portiolna connecting rod comprising means embracing'said Wrist pin and havlng a circumferential groove formed therein adapted to alinewith said circumferential groove in said wrist pin,and a partial'ring embracing saidwrist pin and seated in the groove therein and extending into the groove in said connecting rod means, said groove having ;a depth less than the transverse dimension taken thro ghthe center of a radial v in" 8, The structure set l orth in claim 7 said i wrist pin being capable of endwise movement in sa d piston.

- 9. The combination with a piston of. an automobile engine, of a Wrist pin journaled therein, said wrist pinbeing cylindrical in I form with an uninterrupted cylindrical bore extending therethrough, a connecting rod having a hub portionsurroundlng said wrist pin and engaging the same, said wrist pin having a circumferential shallow groove thereabout substantially midwaybetween its ends, the portion of said connecting rod engaging said wrist pin having a circumferential groove formed therein transversely aligned with the groove in said wrist pin and a partial ring disposed inzsaid respective grooves and'having a cross section fitting and partially disposed in the groove in said wrist pin, said ring acting to prevent movement of said wrist pin lengthwise relatively to saidconn'ecting rod.

In testimony whereof I aifix my signature.

LEO J. MoKONli l. 

